#include <iostream>
#include <unistd.h>
#include <signal.h>
using namespace std;
int f = 0;
void handler(int sig)
{
    cout<<"f = "<<'1'<<endl;
    f=1;
}
int main()
{
    signal(SIGINT,handler);
    while(!f);
    cout<<"success!"<<endl;
    return 0;
}